In the Linux kernel, the following vulnerability has been resolved:

capabilities: fix potential memleak on error path from vfs_getxattr_alloc()

In cap_inode_getsecurity(), we will use vfs_getxattr_alloc() to
complete the memory allocation of tmpbuf, if we have completed
the memory allocation of tmpbuf, but failed to call handler->get(...),
there will be a memleak in below logic:

|-- ret = (int)vfs_getxattr_alloc(mnt_userns, ...)
| /* ^^^ alloc for tmpbuf */
|-- value = krealloc(xattr_value, error + 1, flags)
| / ^^^ alloc memory /
|-- error = handler->get(handler, ...)
| / error! */
|-- xattr_value = value
| / xattr_value is &tmpbuf (memory leak!) */

So we will try to free(tmpbuf) after vfs_getxattr_alloc() fails to fix it.

[PM: subject line and backtrace tweaks]

References

• https://nvd.nist.gov/vuln/detail/CVE-2022-49890
• https://git.kernel.org/stable/c/0c3e6288da650d1ec911a259c77bc2d88e498603
• https://git.kernel.org/stable/c/2de8eec8afb75792440b8900a01d52b8f6742fd1
• https://git.kernel.org/stable/c/6bb00eb21c0fbf18e5d3538c9ff0cf63fd0ace85
• https://git.kernel.org/stable/c/7480aeff0093d8c54377553ec6b31110bea37b4d
• https://git.kernel.org/stable/c/8cf0a1bc12870d148ae830a4ba88cfdf0e879cee
• https://git.kernel.org/stable/c/90577bcc01c4188416a47269f8433f70502abe98
• https://git.kernel.org/stable/c/cdf01c807e974048c43c7fd3ca574f6086a57906